It is common for existing battery packs, such as lithium ion battery packs, to have a low voltage protection circuits integrated into the battery packs. When the battery voltage drops below a predetermined voltage the low voltage protection circuit turns off the battery pack. The low voltage protection circuit then will not let the battery pack resume providing power until the voltage exceeds a predetermined voltage and the battery pack is removed from the circuit and reinserted into the host device. For example, a battery pack having a low voltage protection circuit having a threshold voltage of 6.0 volts will be shutoff by the low voltage protection circuit when the battery pack generates an output voltage of less than 6.0 volts. Even after the battery pack has been removed and reinserted, the low voltage protection circuit will not allow the battery to provide power until the voltage generated by the battery pack exceeds 6.5 volts.
There are several drawbacks associated with such conventional battery packs. Existing devices that use conventional battery packs are forced to stop operating when the conventional low voltage protection circuit removes power. This can be problematic in many situations, such as when data is stored in a volatile memory or when a device shutdown procedure is desired for proper operations.
Another drawback associated with conventional battery packs that include low voltage protection circuits is that the low voltage protection circuits do not account for predictable and momentary high current drain conditions. For example, a printing device may have a high current drain and produce a low output voltage during a printing operation. This momentary low voltage condition may cause the low voltage protection circuit to shut off power, even though the battery pack does not need to be recharged.
Therefore, there is a need in the art for systems and methods that provide better control over how and when power is removed from battery packs during low voltage conditions.